Many resellers choose to have their own name servers for appearance reasons. Using our anonymous name servers of ns1.websitewelcome.com and ns2.websitewelcome.com can be less professional looking for a hosting company

i have a domain with godaddy and if i set it to use their namservers this these are ns1.websitewelcome.com and ns2.websitewelcome.com.

but regardless the domains HOSTINGCOSMOS.COM and domainz.in are not being hosted by anyone and they are not technically hosting any clients which makes them unreliable to use them as hosting any websites as if they let their domains expire your sites may still be online as they are hosted by resellerclub, but you wont have any access to files etc as these would have been through the account of domainz.in and it would be hard to get any backups etc. from resellerclub